Electrical resistivity of HTSC-normal metal interface

It is analytically shown that the specific resistivity rho of the contact layer in a hole-type HTSC abutting upon a metal Me with electronic conductivity is a non-monotonous function of the distance from the interface. The maximum value of rho corresponds to rho(AF) of HTSC in the antiferromagnetic dielectric state at the distance x where the difference between the density of Fermi guest electrons and native holes n(f)(e)(x) - n(f)(h) (()x) - 0. In the case of n(f)(e)(x) - const, the value of contact resistivity r(c) of the HTSC/Me interface can serve as an indicator of changes in n(f)(h)(x), especially the temperature-related ones. The temperature dependences r(c)( T) in HTSC/Pb and HTSC/In interfaces were measured for optimally and lightly doped biphasic bismuth ceramics BiSrPbCaCuO. The anomalies observed in the measured temperature dependences agree with the concept of local pairs existing in the pseudogap phase up to the temperature of depairing, the idea of fluctuation superconductivity, and the transition into the superconducting state. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4791769]